Question

I have a variable line_number_max_digits and I want to use it in string format specification as width token. I have come up with the following code:

print ('{0:>%d}: {1}' % line_number_max_digits).format(lineno + i, chunk)

But I understand that percent formatting will eventually go away from Python. I could use string.Template or use format two times but it would make my code less clear:

print ('{{0:>{0}}}: {{1}}').format(line_number_max_digits).format(lineno + i, chunk)

Which way is considered a good practice in such situations?

Answer 1

There is a limited nesting support.

Example

print('{1:>{0}}: {2}'.format(line_number_max_digits, lineno + i, chunk))